The present invention relates to door latch assemblies, and more particularly, to push and pull door latch assemblies that are typically used in hospitals and other facilities where it is desirable to be able to unlatch and open a door in one motion by pulling or pushing a handle in the latch assembly.
Push/pull type door latch assemblies are known in the art, and enable the user to easily open a door with one hand. These types of door handles enable a door to be opened inwardly into a room by pushing on an outside handle or pulling on an inside handle. Because no rotational movement is required to operate the handles, as is the case with conventional doorknobs, push/pull door latch assemblies are commonly used in hospitals and other institutions, and can be easily used in an emergency by the disabled or by young children.
In current applications, a pull handle of a door latch assembly is mounted on the side of the door toward which the door opens and a push handle of the door latch assembly is mounted on the opposite side thereof. These assemblies typically incorporate a cam which causes the pushing or pulling movement of the handle to rotate an elongate key extending perpendicularly through an opening in a latch cylinder. When rotated, the elongate key withdraws the door latch to release the door. Generally, only a small amount of force in one direction is sufficient to release the latch.
However, because of the generally high-traffic, high-pressure atmosphere in hospitals and the like, both the cam and the handle can become worn down and damaged due to repeated use of the assembly. Every time the door latch assembly is operated, the cam experiences a shock due to the pushing or pulling of the handle, which wears down the cam, particularly when the shock is excessive, as can happen in emergency situations. As either the cam or the handle become worn down, it can become more difficult for a user to push or pull on the door handle, which can lead to dangerous consequences in an emergency situation. These instances reduce the life of the apparatus and require replacement.
Therefore, there exists a need to better protect latch assemblies from the shock experienced during operation of the push/pull door latch assembly, thereby increasing the life of the assembly. There also exists a need to reduce the wear on the latch assembly, so that the ease of operating the push/pull handle remains consistent and reliable despite repeated use.